Being valued at well over a billion dollars means Pinterest has easily surpassed the so-called unicorn status, but being valued at less than it was previously means Pinterest qualifies for another, more obscure piece of venture capitalist lingo.

A New York Times piece about Pinterest's newest valuation refers to the social media company as an "undercorn." The word "undercorn" appears to have been coined circa 2014 by business journalist Dan Primack. Primack's original definition, as chronicled by venture capital blogger Ian Sigalow, pertained to a company which achieved unicorn status (i.e. a valuation over $1 billion) and then fell back below this valuation.

A startup that becomes an undercorn will by definition leave some of its VC backers with a loss on their investment. And it's a blemish on the growth narrative that's at the core of a tech startup's identity.

But the stain may not be permanent. As the New York Times points out, Box and Square both went public as "undercorns" and now each enjoy market caps well above their private market valuations.